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Questions tagged [security]

Content related to computer security., i.e. content about policies, mechanisms, etc. needed make sure data is not leaked or corrupted and services available in all circumstances.

2
votes
0answers
10 views

Why is StreamLocalBindUnlink disabled by default?

I want to enable GPG agent forwarding, and found that StreamLocalBindUnlink is disabled by default on sshd. Why is it disabled by default? Is there any security risk in enabling it? Since X11 ...
0
votes
1answer
20 views

Encrypting Wifi Password When Using Wicd

Inspired by this answer, I'm wondering if there is a (relatively) painless way to "hide" the wifi password(s) that is/are present in the /etc/wicd/wireless-settings.conf file. I travel a lot and ...
22
votes
2answers
24k views

Hiding passwords in wpa_supplicant.conf with WPA-EAP and MSCHAP-v2

My wpa_supplicant.conf looks like this: network={ ssid="Some name" scan_ssid=1 key_mgmt=WPA-EAP eap=PEAP identity="my-user-id" password="(clear text password here)" ca_cert="/usr/share/...
2
votes
3answers
2k views

Why does kdeconnect listen on port 1716/tcp all the time? How to close the port / secure it?

Zenmap shows me that port 1716/tcp is open and sudo fuser -v 1716/tcp tells me kdeconnectd is responsible for it. Why does kdeconnectd have the 1716 port opened all the time? And what would be best ...
1
vote
4answers
57 views

Making my remote SSH more secure

I recently set up SSH access to a small Ubuntu box which I currently log into both from my local network and from offsite. Currently I just have 2 users that are remoting in, but checking my /var/...
7
votes
1answer
2k views

gdm greeter configuration: Exclude all *except* for one specific user

I have Googled this one and tried so many combinations, with no success. I need the GDM login greeter to display one and only one username. In effect, what I need is something like this in /etc/gdm/...
1
vote
1answer
256 views

What rule prevents entering a user namespace from inside a chroot?

# rpm -q --whatprovides /usr/bin/unshare util-linux-2.32-2.fc28.x86_64 # unshare -r # i.e. the above succeeds, where the following does not. What rule causes this? # rpm -q --whatprovides /usr/sbin/...
0
votes
0answers
25 views

is there any reliable linux server hardening service? [on hold]

I need to harden a server. But i not so familiar with this technique. So I resort to a tool or service, my question is this a good practice for middle-level security? or is there better choice for my ...
1
vote
1answer
48 views

What is the package release process at CentOS

What's the process if a security patch is available for a package on CentOS? I'm waiting for bind-9.9.4-74 Since 5 days, there are this commit 'import bind-9.9.4-74.el7_6.1' on https://git.centos....
0
votes
1answer
31 views

Installing Vmware ESX on Solaris server

I have been told to install VMWare ESX on the Solaris server, but I could not find resources about this issue on the web, how is that possible?
1
vote
1answer
21 views

How to disable dontaudit denials in SEAndroid

My application is working in permissive mode, but not in Enforcing mode for SEAndroid. Here i cleared (allowed) all denials,so now there is no denial logs coming in my logcat logs.So it might be ...
0
votes
1answer
34 views

Does intrusion detection system(IDS) make sense on a firewalled web-server?

I'm running Apache on a server with stateful firewall where new IPv4/IPv6 ingress connections are allowed only to TCP ports 80 and 443. SSH is allowed from few trusted hosts and only certain ICMP/...
0
votes
1answer
70 views

How can I prevent against the HiddenWasp trojan?

As people probably know by now, some hackers released a trojan "HiddenWasp" into the Linux world. Article from Intezer: https://www.intezer.com/blog-hiddenwasp-malware-targeting-linux-systems/ So ...
1
vote
0answers
67 views

Disconnecting unwanted remote access

If someone is remotely connected to my single ARM board computer with Debian 32-bit OS, (example: thru hijacking the browser), which connects through a firewall on a separate Orange Pi board, and I ...
-1
votes
0answers
32 views

Are these steps enough to run secure website, please add more and comment on mine? [closed]

Imagine a website served by a web server in front of an App server in front of a database. Now we are not discussing bandwidth saturation attacks or HTTP/S flooding etc. We are only discussing how to ...
3
votes
2answers
670 views

Weird audit2why message caused by SELinux

When I run audit2why to see why there is a failure when trying to upload files via SCP to folder /foo/bar on a remote server which results in access denied to folder /foo/bar, I get the following text:...
-2
votes
1answer
21 views

Security patch update [closed]

If applying the latest patch(example : CESA-2019:0679 - Libssh2 Security Update - CentOS 7 x86_64) will cover the previous patch changes or we need to do it separately?
17
votes
3answers
1k views

What is OpenBSD's pledge in short?

Can someone please describe, for a non-programmer, but IT person, what is pledge? Ex.: there is a program, ex.: "xterm". How can pledge make it more secure? It pledge inside the programs code, or ...
5
votes
0answers
164 views

What network connections are not seen by netstat/lsof/ss?

Network monitoring tools ss, lsof -i, netstat -ltupw and similar have limitations like namespace and thus they don't show the whole machine connections. (for namespace created with ip we can see other ...
9
votes
3answers
22k views

Disable stack protection on Ubuntu for buffer overflow without C compiler flags

I'd like to try some shell codes and I want to disable linux protections. I know I could compile using flags but I know another way exists to disable these protections in general I just can't ...
199
votes
3answers
16k views

Security implications of forgetting to quote a variable in bash/POSIX shells

If you've been following unix.stackexchange.com for a while, you should hopefully know by now that leaving a variable unquoted in list context (as in echo $var) in Bourne/POSIX shells (zsh being the ...
0
votes
0answers
27 views

How to set bluetooth security to none?

I am trying to connect my phone with my raspberry(headless) which runs on this OS. My requirement is,I do not have to enter "yes" manually in the bluez CLI application (which is started by the ...
0
votes
1answer
26 views

How to determine which modules are responsible for spectre_v2?

SERVER:~ # cat /sys/devices/system/cpu/vulnerabilities/spectre_v2 Mitigation: Full generic retpoline, IBPB, STIBP, RSB filling - vulnerable module loaded SERVER:~ # The question: But how to detect, ...
1
vote
1answer
45 views

Why ip_forward is disable by default? any side effect?

I need to forward an interface and I wonder why is disable by default? There is any security issue when I enable it? Is there any side effect when I enable it?
0
votes
1answer
29 views

Elasticsearch fails to start with 'permissions read' error even though read permissions exist

I have a symlink at /etc/elasticsearch/analysis that points to a mounted drive at /elasticdata/fileshare/analysis on Ubuntu 16.04 LTS Azure VM. When I try and start elasticsearch I am getting the ...
1
vote
0answers
50 views

How to update libvirt to passthrough md-clear?

There are new 4 CVE CVE-2018-12130 CVE-2018-12126 CVE-2018-12127 CVE-2019-11091 Debian stretch kernel is vulnerable https://security-tracker.debian.org/tracker/CVE-2018-12130 Even if you get a ...
3
votes
2answers
1k views

SC_ERR_NOT_SUPPORTED(225) with Suricata on CentOS 6.5

I have just installed installed Suricata 2.0.3 RELEASE on CentOS 6.5. I try running it with sudo suricata -c /etc/suricata/suricata.yaml -i eth0 and get the following warning <Warning> - [...
1
vote
4answers
65 views

Is it possible to check for DNS-leaks on unix server?

I run a Ubuntu server where I have a split tunnel for VPN. Which means I have a "normal" connection to the internet for most of my services but also a tunneled connection that only a few services use. ...
0
votes
1answer
70 views

How to handle Nginx and PHP ownership of log files?

I currently am running a Nginx reverse proxy in front of an Apache PHP server on Ubuntu. I have a file, log.txt, in the same directory that I serve PHP files out of for my site. PHP writes to this log ...
8
votes
2answers
660 views

Why does the setuid bit work inconsistently?

I wrote the code: // a.c #include <stdlib.h> int main () { system("/bin/sh"); return 0; } compiled with command: gcc a.c -o a.out added setuid bit on it: sudo chown root.root a.out sudo ...
0
votes
1answer
39 views

How can I unload a filesystem module in a RHEL 7 server in order to harden it?

I'm trying to harden my RHEL Linux server 7 according to the CIS guidelines, so I want to unload the cramfs. I typed the following command: modprobe -n -v cramfs and I got the following answer: ...
1
vote
2answers
138 views

Does using non-root user without password makes system more vulnerable?

Let's say somebody sitting under user (non-admin, not root), but he didn't set up any password for it, only superuser/root has password. Is it bad practice (in context of remote access to a desktop ...
0
votes
0answers
30 views

Install Alpine security updates only

Is there a way to install only security updates for Alpine Linux and its apk packages, skipping updates that don't fix security holes?
1
vote
0answers
29 views

Solution for Auditing File Movement and Usage [closed]

I am a graduate research student at a children's hospital and they have fairly strict rules on how patient data is handled. The general principle is that the data cannot leave hospital hardware onto ...
1
vote
1answer
29 views

Synchronise passwords across devices with pass

I am looking for a simple, open-source password manager for linux with a CLI. It has to have a way of retrieving a password via the command line, so I can use it in several scripts (that sync my email ...
43
votes
7answers
72k views

How do I recursively shred an entire directory tree?

I have a directory tree that I would like to shred with the Linux 'shred' utility. Unfortunately, shred has no -R option for recursive shredding. How can I shred an entire directory tree ...
0
votes
1answer
29 views

Ubuntu Security Patches for Apache2

How do i get the newest version on Ubuntu 18.04 (Longterm Version only!) for the apache2 package? (Please let me know if they apply the security patches from the newer versions backwards and i just ...
0
votes
0answers
27 views

How can I properly use my fingerprint scanner?

I just bought a Thinkpad T430 and installed Linux Mint 19 on it. It's the first time ever I use Linux, so I'm kinda lost. I searched a bit and I found a way to make the built in fingerprint scanner ...
0
votes
1answer
131 views

Are packages on snapcraft inherently safe?

Are packages installed by snap from https://snapcraft.io inherently safe? I heard they are sandboxed. Does that mean they can't change my file system, read my files, etc.?
3
votes
1answer
87 views

How to configure a shutdown at the xth wrong entered password?

Having an encrypted hard drive is all well and good, but chances are that if someone is gonna steal your laptop, it’s probably not going to be turned off. Most likely, it will be stolen in a powered-...
81
votes
5answers
36k views

Why is root login via SSH so bad that everyone advises to disable it?

Everybody on the Internet advises to disable root login via SSH as it is a bad practice and a security hole in the system, but nobody explains why it is so. What is so dangerous in enabling root ...
0
votes
0answers
17 views

How do I protect ports from visibility, using portsentry?

I've been given an assignment by my teacher, saying: "Edit the portsentry.conf. Protect a few ports from visibility outside local net". I've gone through the documentation in the config file, and ...
0
votes
0answers
22 views

Encrypted /boot without UEFI

I have only one, LUKS-encrypted, partition. Is it possible to boot system from /boot on this partition? I don't want to use UEFI to do this. EDIT I'm using GRUB. I have uncommented ...
7
votes
1answer
11k views

using sudoers to allow non-privileged user to restart apache

We have production centos servers that run apache as root to allow low port numbers (80 and 443). We'd like a secure way for non-root users to restart apache. Are there any security implications ...
-1
votes
1answer
35 views

hidden files and directories warnings

I received these rkhunter results; what are these files, and are they dangerous? [23:17:48] Checking for hidden files and directories [ Warning ] [23:17:48] Warning: Hidden file found: /etc/....
84
votes
1answer
15k views

Chrome: DNS requests with random DNS names: malware?

Over the years (since 2005), I have seen logs of strange random DNS requests done, on the multiple DNS / BIND servers I have maintained. May 7 12:13:50 1.1.1.1 named[63742]: client 1.1.1.2#24123 (...
2
votes
1answer
135 views

sedutils vs hpdarm for SED hard disks

According to my reading there are 2 known methods for using Self-Encrypting Drives (SED): hdparm https://www.pugetsystems.com/labs/articles/Introduction-to-Self-Encrypting-Drives-SED-557/ sedutils ...
2
votes
2answers
530 views

How to ban all connections to .se and .ru in the hosts.deny file

I am trying to figure out, whether or not it's possible to make sure, that if a user uses a browser and types in a domain name that ends on either "se" or "ru", they will be denied access to that site....
2
votes
1answer
2k views

Any better alternative to chroot on an OpenVZ VPS?

Are there any better alternative to chroot environment? I'm thinking about running nginx on a jailed environment. BTW, I'm on OpenVZ VPS, so modifying the Kernel is a no-no. (I think that prevents ...